Re: [rdiff-backup-users] Pretty pictures and new version of proposal

[John Goerzen]

On Mon, Sep 29, 2003 at 12:25:56PM -0700, Ben Escoto wrote:
> Well, if something like gnupg is used, it already gives you the option
> of signing (as well as encrypting) input data, so this method could be
> used on all of the blocks.  Similarly, I think gzip puts some CRC
> check by default into its output.  So I think bits getting flipped
> will be noticed pretty early.

What if you're not using encoding at all?  Also, it would be good to have a
post-decode checksum to ensure everything worked.  Some formats may not be
able to detect if they have not decoded the entire original file, for
instance.

> However, the format is pretty fragile if a block becomes too long or
> too short.  That would mess up all the lengths and could make the rest
> of the archive unreadable.  However, other formats like tar don't seem
> to be robust in this way either, and maybe those kinds of errors don't
> happen very much (?).

tar actually is pretty resiliant in the face of this, and GNU tar can
recover from such a problem usually with only spoling the effected file and
perhaps those on either side of it.

-- John